extern int generic_readchar (struct serial *scb, int timeout,
int (*do_readchar) (struct serial *scb,
int timeout));
-extern void reschedule (struct serial *scb);
extern int ser_base_flush_output (struct serial *scb);
extern int ser_base_flush_input (struct serial *scb);
extern int ser_base_send_break (struct serial *scb);